The present invention relates to optical elements and a method for manufacturing the same.
As optical elements, those having a structure that includes a substrate, a columnar section for light emission or incidence formed above the substrate, a resin layer formed above the substrate and around the columnar section, and an electrode that passes over the resin layer and is electrically connected to an upper surface of the columnar section are known (Patent Document 1). According to this, the resin layer of a constant thickness is present between the substrate and the electrode, such that the parasitic capacitance of the optical element can be reduced, and the high-frequency property can be improved.
However, because thermal expansion coefficients of the columnar section (semiconductor element) and the resin layer are different, a stress may be concentrated at an interface of the two. More specifically, the resin layer has a greater amount of contraction due to heat than that of the columnar section, such that the resin layer may peel off the columnar section as a result of contraction of the resin. By this, the electrode may be disconnected at the interface of the resin layer and the columnar section, which lowers the reliability of the optical element.
[Patent Document 1] Japanese Laid-open Patent Application 2003-332682.